8215369: Jcstress pollute /var/tmp with temporary files.

Reviewed-by: iignatyev, mseledtsov

test/hotspot/jtreg/applications/jcstress/JcstressRunner.java

@@ -89,6 +89,11 @@ public class JcstressRunner {
     private static String[] getCmd(String[] args) {
         List<String> extraFlags = new ArrayList<>();
 
+        // java.io.tmpdir is set for both harness and forked VM so temporary files
+        // created like this File.createTempFile("jcstress", "stdout");
+        // don't pollute temporary directories
+        extraFlags.add("-Djava.io.tmpdir=" + System.getProperty("user.dir"));
+
         // add jar with jcstress tests and harness to CP
         extraFlags.add("-cp");
         extraFlags.add(System.getProperty("java.class.path")
@@ -97,16 +102,11 @@ public class JcstressRunner {
 
         extraFlags.add(MAIN_CLASS);
 
-        String[] javaOpts = Utils.getTestJavaOpts();
-        // disable flags auto-detection
-        if (0 == javaOpts.length) {
+        extraFlags.add("--jvmArgs");
+        extraFlags.add("-Djava.io.tmpdir=" + System.getProperty("user.dir"));
+        for (String jvmArg : Utils.getTestJavaOpts()) {
             extraFlags.add("--jvmArgs");
-            extraFlags.add("");
-        } else {
-            for (String jvmArg : Utils.getTestJavaOpts()) {
-                extraFlags.add("--jvmArgs");
-                extraFlags.add(jvmArg);
-            }
+            extraFlags.add(jvmArg);
         }
 
         String[] result = new String[extraFlags.size() + args.length];